Don't Fall Victim To The Commonest Causes Of Food Poisoning

The Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia estimates that about 48 million people in the US (that’s one in six of us) are poisoned every year by contaminated food. In 128,000 cases the illness is severe enough to require hospital treatment, and results in the death of 3,000 people. Food poisoning has sadly even led to the death of unborn fetuses. 

The variety of foodstuffs affected is staggering.  It includes obvious culprits such as meat, raw fish, and cheese, but also peanut butter and pet food.  A network of regulatory and enforcement agencies, and laboratories strive to keep pace with the scale of the problem. 

 This is because many people do not seek medical attention for food poisoning and of those who do, not all will have a sample sent to a lab. or be notified to the relevant authorities - in other words they go unreported. 

For example for every case of Salmonella food poisoning notified to the authorities in 2012, the CDC estimate a further 29 went undiagnosed, and in the case of Vibrio (a common contaminant of oysters) for every case reported, 142 went undiagnosed!

Which bacteria are causing the problem?

The spectrum of organisms (bacteria and viruses) isolated from food linked with food poisoning varies from year to year.  But some species generally always feature.  In 2012 the most common was Salmonella, closely followed by Campylobacter, then Escherichia coli (especially strain 0157), Vibrio, Yersinia and Listeria.

Which foods are most associated with food poisoning?

The FDA produced a report of the foods most commonly reported to them in relation to outbreaks of food poisoning.  

The most common organism associated with them was Norovirus.  The source of this contamination is generally from food handlers, in other words, good hygiene practices are not being employed by people handling the produce.

But leafy greens can also be contaminated with E. coli while growing - from contact with wild animals, manure or unclean water.  They can also acquire the organism during food preparation – from other foods which are contaminated with E.coli.  This is often how outbreaks in restaurants have occurred – in those where food preparation practices are poor, allowing cross-contamination between foods.

Contaminated poultry was the most common cause of death

The FDA reported that in 2012 the most common cause of death due to food poisoning was poultry contaminated with salmonella.

Salmonella poisoning

This is a bacterium found in the intestines of birds and animals and is a frequent contaminant of eggs, because the organism is excreted by poultry.  Poor hygiene practices by egg producers can lead to contamination of eggs.

But healthy animals have been found to harbor salmonella species in their ovaries, which are then incorporated into the eggs at a much earlier stage.

The largest proportion of food poisoning from contaminated eggs occurred in restaurant food. 

Salmonella found in a range of foods

Contamination with this organism was not limited to poultry and eggs. It was also associated with eating raw scraped ground tuna (imported into the US), a particular brand of peanut butter (also imported), ground beef and dried dog food.  In the case of the dog food, it was felt that pet owners were infected both from handling the food and also from shedding of the organism by their pets (who were unaffected by it, but became carriers).

Imported food increasingly to blame

Many of these cases highlight the fact that more cases of food poisoning are associated with imported food than in previous years.  There are safeguards in place where the FDA inspect produce entering the country, but some unscrupulous distributors despatch the food before it has been officially checked and given the ‘OK’.

How can food poisoning lead to death?

The symptoms of those unfortunate enough to suffer food poisoning as a result of eating these contaminated foods varied from a couple of days of diarrhea and stomach cramps, to kidney failure and even death.

There are two main reasons for the variation in severity of illness.  The first is that some of the organisms are able to spread from the gut to the lymphatic system, which is part of our immune system and linked to the circulation.

The second reason for the variation is the ability of the person affected to fight the infection and to tolerate the effects of the illness.  Prolonged diarrhea and/or vomiting lead rapidly to serious loss of fluid which can quickly be fatal, if untreated, in the old and very young.

Simple ways to avoid food poisoning

The CDC summarizes its advice into five headings:

CLEAN hands, surfaces and utensils by frequent washing. Use soap and water for hand-washing and pay particular attention to the backs, between fingers and under fingernails.

Thoroughly wash fruit and vegetables – even those you’re going to peel. Do not wash meat, poultry or eggs.

SEPARATE raw meat, poultry, seafood and eggs from ready-to-eat foods, to avoid cross-contamination. Keep separate when buying, and in the fridge. Use separate equipment and surfaces for preparation.

COOK to the right temperature, using a special thermometer for meat and keep food hot while being served and eaten.  Egg yolks should be cooked until firm. Microwave food thoroughly (to 165°F).

CHILL food promptly, especially in hot weather. Defrost frozen food in the fridge – not on the kitchen counter or in the sink.

REPORT suspected food poisoning to your local health department (see link below).